Scholastic test and grading apparatus

ABSTRACT

Scholastic test grading apparatus uses a circular answer sheet having a circular series of angularly-spaced, numbered rows of radially-spaced answer spaces on which the student marks his answers to correspondingly numbered questions by blacking-in selected ones of the answer spaces as with soft pencil lead. The sheet also carries punch locating indicia opposite each number. The answer sheet is graded by pressing it, in a selected orientation, against a printed circuit board which has formed thereon a pattern of electrical gaps corresponding to the correct-answer positions on the answer sheet. The blacked-in pencil lead blacking material in such positions bridges the electrical gaps to close electrical circuits to a circle of lamps, which light up to show both how many and which answers are correct. A question label disk placed in the circle of lamps identifies the questions or groups of questions indicated by the several lamps. 
     The circular shape and arrangement of the answer sheet permits it to be oriented in numerous angular positions against the printed circuit board, so as to give different correct answer locations for different tests without changing the pattern of gaps on the circuit board. A designated orientation for each test is obtained by punching holes at selected pairs of the punch locating indicia and engaging the holes over fixed locating pins. 
     The grading apparatus supports the printed circuit board over a pressure pad which may be manually retracted and latched downward to define a slot for insertion of the answer sheet and which, when released, is spring-pressed upward to press the sheet against the circuit board. The circuit board is a plug-in unit which is readily replaceable to change correct-answer patterns. 
     The electrical answer-indicating circuits each contain a lamp and a resistance, and operates at relatively high voltage, e.g. 100 v., so as to ensure reliable circuit closure by the blacking material in the answer spaces, and such circuits are isolated from line voltage by an isolating transformer.

BACKGROUND OF THE INVENTION

This invention relates to scholastic test grading apparatus, andespecially to apparatus for quickly and easily evaluating answers todifferent scholastic examination units without adjustment of the machineanswer code.

Automatic test grading machines have recently become popular for gradingmany types of student examinations. These are especially useful inscoring examinations wherein multiple-choice or true/false answers areindicated upon standardized answer sheets. Prior grading machinescomprise fairly complicated and expensive electrical and mechanicalapparatus which compare student responses with an answer code andprovide a performance readout such as a number indicating how manyquestions were correctly answered.

In modern education, students are frequently encouraged to proceedthrough sequential courses of study at an individually-set pace, and totest themselves on each subject unit as soon as they feel they havemastered the material of that unit. In such practice, it is desirable toprovide test and grading apparatus which will accommodate many studentscompleting different examinations simultaneously, and to provideinexpensive and easy to operate grading apparatus which will scoredifferent examinations with little or no machine adjustment from oneexamination to another.

In the prior art, U.S. Pat. No. 3,407,516 proposes a test grading systemwhich utilizes answer cards on which the student indicates his responsesto test questions by punching holes at selected locations. The punchedanswer card is then graded by superimposing it on a test code card whichhas perforations therein arranged according to the correct responses tothe test questions, and both cards are inserted into a machine forscoring. In the machine, a series of contact fingers sense matchingholes and register one count whenever the perforations in the two cardscoincide. Such machines do not indicate to the student which questionswere answered correctly and which were not, and this is especiallydisadvantageous for grading self-administered, progress tests used insequential study courses. Moreover, the machine requires a separateanswer code card for each different examination, and one of these cardsmust be inserted into the machine each time an answer card is inserted,which makes a machine of this type both complicated and time consumingto use.

Other grading machines have been proposed which provide a plurality ofself-contained answer codes. These machines may use a standardizedanswer card on which the student indicates his responses to testquestions by blacking-in selected ones of a series of blocks with pencillead. In U.S. Pat. No. 3,631,611, for example, such an answer card isgraded by bringing it into contact with a series of spaced contactfingers which are electrically connected according to a preset answercode. Each correctly located answer marking on the card completes acircuit through a pair of the fingers to energize a counter forregistering the total number of correct answers, and to energize amarking device which marks the correct answers. While machines of thistype do not require answer codes to be maintained apart from the machineitself, they do require the machine to be provided with marking meansand means to change the answer code, and require changing the answercode whenever a card from a different examination is to be graded. Suchprovisions make the machine complicated and expensive, and its use isparticularly time consuming and undesirable when students are followingmodern, individualized programs of study and are thus completing manydifferent examinations at the same time.

The present invention provides an inexpensive grading apparatus which iseasy to use, which tells the student not only how many but which answersare correct and incorrect, and which permits different tests to bescored in different ways without machine adjustment.

SUMMARY OF THE INVENTION

Test and grading apparatus in accordance with the invention comprises acircular answer sheet which carries a series of angularly-spaced rows ofradially-spaced answer spaces, on which a student may indicate hisanswers to a corresponding series of multiple-choice or true/falsequestions by blacking-in a selected answer space in each row with a softlead pencil. Desirably, the rows of answer spaces are numbered tocorrespond to the questions, and the answer spaces of each row may beidentified by letters. The answer sheet also carries a circumferentialseries of orientation code indicia, which are desirably a series ofpunch locations respectively adjacent the several row numbers.

Apparatus for grading or scoring the answer sheets comprises a sensingpanel which carries electrical contact elements that form a series ofangularly-spaced electrical gaps in a predetermined pattern atradially-spaced positions corresponding to the correct-answer positionsin the rows of answer spaces on the answer sheet. The relationship issuch that when a completed answer sheet is pressed against the sensingpanel in a proper orientation, the correctly blacked-in answer spaceswill overlie the electrical gaps and the blacking material therein willbridge the gaps and close electrical circuits to a circle of lamps whichindicate how many and which correct answers have been given. A questionlabel disk placed in the circle of lamps identifies the questions orgroups of questions indicated by the several lamps.

Because of the circular shape of the answer sheet and the circulararrangement of the answer-space rows and the pattern of electrical gaps,the answer sheet may be pressed against the sensing panel in any ofnumerous angular orientations. Such different orientations have theeffect of producing different positions of correct answers on the answersheet, and permit different correct-answer positions to be used on anumber of different tests without changing the pattern or code of theelectrical gaps on the sensing panel. Selected different orientations ofthe answer sheet relative to the sensing panel, for different tests, areobtained by aligning selected orientation indicia on the answer sheetwith predetermined locating points relative to the sensing panel.Preferably, this is done by providing a pair of locating pins in fixedpositions relative to the sensing panel, and orienting the answer sheetthereon by means of a pair of holes which are punched in the answersheet at punch locations selected to match the test being answered. Suchholes are desirably punched after the student has completed the answersheet so that he previously has no way of knowing which orientation willbe used in grading his answer sheet on the particular test being taken.

In accordance with the invention, the preferred apparatus for gradingthe answer sheets comprises a housing which defines a narrow, preferablyhorizontal, slot to receive an answer sheet, and is provided with a pairof locating pins for locating and orienting the sheet in the slot. Thesensing panel is mounted above the slot and desirably is in the form ofa printed circuit board on which the electrical gaps have been formed ina predetermined pattern. A pressure plate is mounted below the sensingpanel, is spring pressed upward to press the answer sheet against thesensing panel, and is connected to a manually operated lever whichretracts it to permit insertion of the answer sheet in the slot. Theprinted circuit board is desirably a plug-in unit which is readilyreplaceable to change correct-answer patterns.

The electrical answer-indicating circuits of the apparatus desirablyoperate at relatively high voltage, for example, at 110 volts, so as toensure reliable circuit closings by the blacking material in the answerspaces. The circuits each desirably contain a high resistance in serieswith the indictor lamp, to permit use of glow lamps of high reliabilityand long life. The operating circuits are desirably isolated from linevoltage by an isolating transformer.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate the invention, and show a preferredand exemplifying embodiment. In such drawings:

FIG. 1 is an isometric view of a test grading machine of this invention,with portions thereof broken away;

FIG. 2 is a plan view of an answer sheet for use with the gradingmachine shown in FIG. 1, with certain answer spaces shaded to representanswer markings;

FIG. 3 shows a portion of a test code sheet for use with the gradingmachine shown in FIG. 1;

FIG. 4 is a plan view of an electrically conductive laminate pattern onthe underside of the circuit board, as seen from above the circuit boardfor superimposition on the answer sheet shown in FIG. 2;

FIG. 5 is a longitudinal vertical section of the test grading machineshown in FIG. 1;

FIG. 6 is a fragmented horizontal section of the machine taken on theline 6--6 of FIG. 5, with portions thereof broken away;

FIG. 7 is a transverse vertical section of the machine taken on the line7--7 of FIG. 5;

FIG. 8 is a horizontal section on the line 8--8 of FIG. 5 with portionsbroken away to show the electrically conductive laminate pattern on theupper side of the circuit board; and

FIG. 9 is a schematic representation of the machine electrical circuit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Test grading apparatus embodying the invention is shown in FIG. 1 andgenerally comprises a grading machine 10 having a lower housing 12 withan upper sensing panel 14 mounted thereon in a manner to provide aforwardly open slot 16 for reception of a circular test answer sheet 18.The top face of the slot 16 is defined by a sensing panel, here shown asa circuit board 22 which has sensing means on its bottom side forsensing correctly-marked answers on the answer sheet 18 and for formingcircuits to energize lamps 24 mounted in a circle in the top of thepanel 14 to indicate the correct answers. The lower housing 12 containsa pressure plate for pressing the answer sheet against the circuit board22, and such plate is controlled by a manually operated control arm 20.

A test answer sheet 18 for use with the grading machine 10 is shown inFIG. 2, and comprises a circular paper sheet of a convenient thicknessprovided with a central area for student and test identification data.The circular portion of the sheet surrounding such central area isprinted to provide a series of angularly-spaced rows 28 ofradially-spaced answer spaces 30. The rows 28 are numbered with printednumbers 32 to correspond to numbered test questions, and the answerspaces 30 are identified by the letters A, B, C, and D, to correspond tosimilarly identified possible responses to the test questions. The testquestions will normally be either multiple-choice or true/falsequestions to which answers can be indicated by marking one or more ofthe answer spaces 30. The particular number of answer rows as well asthe number of answer spaces within each row may vary, but in practice,it has been found that an answer sheet having a diameter of about eightinches readily accommodates 25 answer rows having four answer spaceseach.

In using the answer sheet 18, a student indicates his response to eachtest question by blacking-in with a soft lead pencil a selected one ofthe answer space A, B, C, or D of the row corresponding to the question.Such blacked-in spaces are shown by shading on the answer sheet in FIG.2.

The answer sheet 18 also carries a circular series of orientationindicia, here shown as a ring of round punch markings 34 printed aboutthe periphery thereof and respectively adjacent the numbers 32 of therows 28. Such markings 34 are used to fix the orientation of the answersheet 18 in the grading machine. To this end, after completion of thetest by a student, a pair of apertures are punched in the sheet at twoselected and generally opposite markings 34a and 34b, in accordance witha predetermined code for the test being graded. The test unit isidentified by a number recorded in the identification area at the centerof the sheet, as at 36 in FIG. 2. The punching code is desirablyrecorded on a master code sheet 38, such as that shown in FIG. 3, andthis indicates which pair of the markings 34 are to be punched for eachdifferent test unit. For example, FIG. 3 shows that for test unit number16, the orientation apertures are to be punched through the orientationcode markings 34 adjacent the answer rows numbered 1 and 13, and suchpunchings are shown in FIG. 2.

The answer sheet 18 is scored by inserting it into the forwardly openslot 16 of the grading machine 10 with its printed and pencil-markedface upward, as shown in FIG. 1. The sheet is located and angularlyoriented within the slot by positioning the apertures punched thereinover a pair of locating pins 39 mounted on the machine 10 at oppositesides of the sensing panel 14. After the answer sheet 18 is properlylocated and oriented in the slot, the sheet is pressed into contact withthe sensing means on the underside of the circuit board 22 for scoring,as will be described below. In the apparatus shown, there are 25possible angular orientations of the answer sheet 18 within the slot,equal to the number of answer rows 28 printed thereon. A correspondingnumber of different sets of answer positions on the answer sheets willbe available for use with different tests or test units, and thedifferent angular orientations to be used for the different test unitswill be shown by the master code sheet 38.

The sensing means on the underside of the circuit board 22 comprises acopper laminate gap pattern which can be photographically etched on theboard in a conventional manner. One such gap pattern 40 is shown by wayof example in FIG. 4, and for convenience, said pattern 40 is shown asviewed from above the circuit board for superimposition over the answersheet 18 shown in FIG. 2. Such gap pattern has a central common contactarea 42 connected to a lead 44. At angularly spaced positions about itsperiphery, such central contact area has edge portions or arms 46 whichextend outward to one or another of four circles A, B, C, and D, shownin dotted lines, and there lie in spaced relation with individualcontact areas 50 so as to form narrow gaps 48 on and along such circles.The circles have radii equal to the distance from the center of theanswer sheet to the answer spaces A, B, C, and D thereon. The gaps 48are thus radially-spaced in the same positions as the answer spaces, andthey are also angularly spaced to register with the rows 28 of answerspaces. The position of the gap 48 along each row 28 of answer spacesdetermines which space will represent the correct answer to the questioncorresponding to that row. The relationship of the gaps to the circles,i.e., as to which circles the gaps overlie, is a random relationship, sothat there will be no regular pattern of correct-answer positions whichstudents can discern.

Each individual contact area 50 is connected to an electrical lead whichis connected in circuit with one of the indicator lamps 24, as will bemore fully discussed below. When the gap 48 in a circuit is bridged by ablacked-in pencil marking on the answer sheet, this completes anelectrical path between the contact areas 46 and 50 and completes thecircuit and lights the lamp. The lamps of the several circuits arearranged in a circle in the same circumferential order as the gaps 48 onthe board and hence in the same order as the corresponding answer-spacerows 28 on the answer sheet, and the series of lights thus has apredetermined relation to the series of answers on the answer sheet,which relation depends, however, on the orientation of the answer sheetrelative to the circuit board.

When the answer sheet 18 is pressed into contact with the printedcircuit 40 on the circuit board, the rows 28 of answer spacesrespectively lie radially across the several gaps 48 of the printedcircuit. If a question for each row has been correctly answered, theblacked-in answer space representing the correct answer will be radiallypositioned on the gap so as to bridge the gap in that angular positionand complete the electrical path between the center contact area 46 andthe individual contact area at that position. This will light the lampin circuit with that gap and give a visual indication of the correctresponse. For example, referring to FIGS. 2 and 4, the student responsefor question No. 21 is indicated on the sheet shown in FIG. 2 by thepencil-blackened area A at the outermost answer space 30a of the 21strow of spaces. For test unit number 16, the gap representing the correctanswer to question No. 21 is the correspondingly located gap 48a whichlies on the outermost circle A in FIG. 4. Accordingly, when the sheet isbrought into contact with the laminate pattern, the row 21, space Aresponse bridges the gap 48a and completes the electrical path betweenthe contact areas 46a and 50a to light the lamp 24 corresponding toquestion No. 21. Similarly, the student response to question No. 23 isshown by the blacked-in C answer space in row 23 on the answer sheet.However, the gap 48b corresponding to a correct answer to question NO.23 is at the innermost or D position, and the C response is not properlylocated to bridge the gap 48b, and accordingly, the lamp 24corresponding to question No. 23 will not light but will remain dark toindicate an incorrect answer.

The random radial arrangement of the gaps 48 on the laminate pattern 40thus defines an answer code sequence, while the angular orientation ofthe answer sheet within the slot and with respect to the laminatepattern 40 determines the specific answer code for a particularexamination unit. The number of possible specific answer codes isdetermined by the number of orientation positions which the answer sheetcan have, and this is determined by the number of answer rows 28 on thesheet 18 and the corresponding number of angularly spaced gaps in thepattern. The specific answer code is changed simply by orienting theanswer sheet in a different orientation with respect to the series ofgaps 48. No internal machine adjustment is required, and differentorientations for different tests are obtained by punching differentparts of locating holes in the answer sheet, in accordance with a codeguide as shown in FIG. 3, as the sheet is prepared for insertion in thegrading machine.

The grading machine 10 shown in FIGS. 1 and 5-7 has a lower housing 12and an upper sensing panel 14 mounted as a cantilever on the lowerhousing 12. The lower housing is a generally rectangular box having ahorizontal bottom wall 52 and vertical end and side walls 54 and 56. Itdesirably has rubber mounting feet 58 at its corners. The top of thehousing is provided with flat horizontal border portions to define thelower face of the slot 16 and to support the edges of the answer sheet18 inserted therein. To provide such border portions, an angle member isbolted to the front end wall 54 by bolts 57 and provides aforward-extending lip 55. At the sides, the border portions are providedby the top flange of a pair of angle iron side-rails 60 which are boltedagainst the inner faces of the side walls 56 and run longitudinally thefull length of the housing 12. Such side rails 60 also serve as asupport for the cantilever upper panel, as will be described. The answersheet locating pins 39 are mounted on the horizontal legs of the siderails 60 and extend upward therefrom in locations at opposite sides ofthe machine and outward from the sides of the sensing panel 14.

The pressure plate for pressing the answer sheet 18 upward into contactwith the underside of the circuit board 22 is mounted within the lowerhousing 12. Such pressure plate comprises a rectangular platform 86carrying a resilient pressure pad 88 of rubber or the like on its uppersurface, and lies between the side rails 60.

The pressure pad 88 is desirably annular in shape and of a size to bearagainst that portion of an answer sheet which lies against the area ofthe circuit board which carries the electrical gaps 48, so as toconcentrate the pressure of the pressure plate on the portions of theanswer sheet which carry the answer markings and which engage theelectrical gaps on the circuit board. The mounting mechanism for thepressure plate comprises a supporting beam of angle stock 68 extendinglongitudinally along the center of the housing bottom wall 52 forsubstantially the entire length of the machine. Such angle stock has ahorizontal leg mounted against the bottom wall 52 by a pair of spacedbolts 72, held by nuts 74 and extending upward therefrom. The upper endsof the bolts 72 serve as locating posts for a pair of verticallyextended springs 78. The upper ends of the springs 78 are received overbolts 80 mounted in nuts 82 welded to the underside of the platform 86of the pressure plate. The springs normally tend to press the pressureplate upward against the circuit board 22.

To control the position of the platform 86, a pair of laterally spaced,downward extending posts 90 are connected as by welds 92 to theunderside of the platform. The supports 90 are pivoted at their lowerends to a transverse crank bar 94 which is rigidly connected by a pairof crank arms 96 to a transverse control shaft 98. As shown, the bar 94is disposed to the rear of the shaft 98 and parallel therewith. Thecontrol shaft 98 is mounted in bearings 100 formed from nylon or thelike and fastened by bolts 102 to the side walls 56 of the housing. Theshaft ends extend laterally outward from the bearings through thehousing side walls, and are fixed by pins 104 to the ends of theU-shaped control arm 20. Collars 103 are welded to the control arm 20and bear against the side walls 56 to prevent axial displacement of theshaft 98. From the ends of the shaft 98, the side legs of the controlarm 20 extend rearward along the housing side walls, and the transverseleg of such arm forms a handle behind the rear wall of the housing.

The platform is releasably retained in a lowered position away from thecircuit board 22 by a latch 105. Said latch is pivotally mounted by apin 106 to the vertical leg of the angle stock 68 at the bottom of thehousing, and extends upward beneath the center of the platform behindand adjacent to the crank bar 94. The latch has a forward projectingfinger 108 at the top thereof which is received over the crank bar whenthe platform is in a lowered position, as shown in FIG. 5, to releasablylock the platform away from the circuit board.

The latch 105 is controlled by an actuating rod 110 which has one endpivotally connected to the latch 105 at a point between the latch pin106 and the latch finger 108. The rod 110 extends rearward through abushing 111 mounted in the rear end wall 54 of the housing, and carriesa handle 113 at its rearward end. A spring 112 surrounding the rearportion of the rod 110 bears against a fixed plate 115 adjacent the rearwall and engages a flange 114 fixed to the rod to urge the rod forwardtoward latched position.

The pressure plate 86-88 is normally held in lowered position by theengagement of the latch 105 with the crank bar 94, against the action ofthe springs urging the plate upward toward the circuit board 22. Whenthe grading machine is to be used to grade an answer sheet, such sheet18 is inserted in the slot between the pressure plate and the circuitboard, the handle of the control arm 20 is slightly depressed to releasethe pressure of the crank bar on the latch 105, the handle 113 is thenpulled out to move the latch to release position, and the control arm 20is then allowed to swing upward, preferably at a manually limited rate.This allows the pressure plate to move upward under the influence of thesprings 78, and when the control arm is fully released, the pressureplate presses the answer sheet against the circuit board with fullpressure determined by the force of the springs. When the grading iscompleted, the handle of the control arm 20 is pressed downward to lowerthe pressure plate, and the latch 105 then automatically engages thecrank bar 94 to hold the pressure plate in lowered position as shown inFIG. 5. The forward lower surface of the finger 108 may be rounded, asat 118, to facilitate such engagement.

The upper sensing panel 14 mounted on the lower housing 12 comprises ahorizontal top wall 120, a rear end wall 122, and two side walls 124.The width of the panel 14 is less than the width of the housing so thatthe locating pins 39 are disposed laterally outward from the panel sidewalls 124. The panel 14 extends as a cantilever in unsupported relationover the front portion of the housing 12, to define the top of the slot16, and is rigidly connected to the housing structure over its rearportion. To this end, such top panel 14 is rigidly preassembled to theangle iron side rails 60 which bolt to the side walls 56 of the housing,by means of elongated angle-iron brackets 128 extending from the rear ofthe housing forward to the rear edge of the slot 16. Such brackets 128have horizontal legs 127 (FIG. 7) which underlie the top flanges of theangle iron side rails 60 and are welded thereto as at 130, and havevertical legs 129 which lie against the inside faces of the side walls124 of the top panel and are welded thereto as at 132. When thesub-assembly of the top panel with the angle iron side rails 60 isassembled to the housing, the side rails 60 are bolted to the side wallsof the housing and the rear wall 122 of the panel is bolted to the rearwall of the housing as by bolts 126.

As shown in FIGS. 1 and 7, the panel side walls 124 have their loweredges turned horizontally inward forward of the brackets 128 to providelips 134 to support the circuit board 22, and to define the top of thehorizontally extending slot 16 between the panel 14 and the housing 12.In practice, the vertical width of said slot is about 1/16 to 1/4 inch.The circuit board 22 has a width slightly less than the width of thepanel 14, and is slidably received into the forward end of said panel ina track formed by the lips 134 and a horizontally extending backingplate 136. The backing plate 136 is formed from an electricallynon-conductive material, and has its lateral edges interconnected to thepanel side walls 124 by opposed pairs of brackets 137, as shown in FIGS.7 and 8. The brackets are connected to the side walls by bolts 139 andto the backing plate by bolts 141. Desirably, said bolts 141 have theirheads inset into the plate 136 so that they do not interfere withsliding of the circuit board within the track.

The rear edge of the circuit board narrows in width, as shown in FIGS. 1and 8, for plug-in reception into a conventional printed circuit boardconnector 148 having a plurality of lower and upper wiper contacts 149and 151. The connector is mounted by screws 150 on a transverse metalplate 152 welded by welds 153 to the inside faces of the vertical legsof the brackets 128.

The forward edge of the circuit board is connected by screws 135 to asupport bracket 137. The bracket 137 is in turn connected to avertically extending face plate 138 having a pair of handles 140 mountedthereon. Said plate 138 serves to close the forward face of the upperpanel 14 when the circuit board is received therein. This circuit boardmounting permits insertion and removal of the board for replacement by adifferent circuit board having a different gap pattern thereon to beinstalled in the machine. Conveniently, a key-operated lock cylinder 142is mounted in the top wall 120 of the panel 14, and has a locking arm144 which engages a finger 146 mounted on the support bracket 137 toreleasably lock the circuit board in the upper sensing panel and toprevent unauthorized access to the answer code defined by the gappattern. Alternatively, the circuit board can be bolted in positionwithin the upper panel to prevent easy removal of the circuit boardtherefrom.

With the circuit board 22 locked in position within the upper sensingpanel 14, each set of the contact arms 46 and 50 defining a gap 48 onthe laminate pattern 40 is electrically connected through the circuitboard connector 148 to one of the lamps 24. As shown in FIGS. 1, 5, and7, said lamps are mounted in a circular series of sockets 25 in holesformed in the top wall 120 of the sensing panel. Desirably, the lampsare angularly spaced in the same positions and in the same order as thegaps 48 on the laminate pattern 40 of the circuit board to providecorrelation between the lighted lamps and the test questions.

The interconnections between the contact arms 50 of the circuit boardand the lamps 24 are shown in FIGS. 2, 4, 8, and 9. The contact arms 50which are nearest the circuit board connector 148 have printed leadconnections 51 which run along the underside of the circuit board to therear edge thereof for connection with the lower wiper contacts 149 inthe connector 148. Also, the power lead 44 connected to the centralcontact disk 42 runs along the underside of the board to the rear edgethereof for connection with one of the lower wiper contacts 149. Thecontact arms 50 farthest from the connector 148 have lead connectionswhich run away from the central disk 42 to individual terminal points154. At such terminal points, the leads are connected upward through theboard to a series of straight leads 156 on the top thereof which run tothe rear edge for connection to the upper wiper contacts 151 in theconnector 148. Conveniently, the straight leads 156 are copper laminateleads formed on the upper side of the circuit board in a conventionalmanner, such as by photographical etching. The terminal points 154 aredesirably positioned ahead of the backing plate 136, as shown in FIG. 8,to prevent them from being damaged as the circuit board is inserted intoor removed from the sensing panel. A series of wire leads 158 areconnected to the contacts 149 and 150 of the circuit board which engagethe printed lead connections 51 and 156, and a wire lead 172 isconnected to the contact 149 which engages the power lead 44 to thecentral contact disk 42 on the circuit board.

The wire leads 158 and 172 are connected in circuits as shown in FIG. 9.Power supply is from a supply cord 164 having a plug for connection to astandard 110 v. AC receptacle. The cord is connected through a controlswitch 166 mounted on the rear end wall 54 of the housing, and through afuse 168 to the primary of a one-to-one isolation transformer 170. Thesecondary of such transformer is connected at one side to the wire lead172 which connects through the contact connector 148 to the center disk42 of the laminate pattern and at the other side to a common return lead159 from the lamp sockets 25. The several wire leads 158 from theconnector contacts 149 and 150 are each connected through a resistor 160to the opposite side of a lamp socket 25. The connections to theresistors are desirably at connection points on terminal strips 162suspended from the panel top wall 120. The lamp circuits are all alikeand parallel, and the two shown in FIG. 9 are representative of theothers.

Desirably, the lamps 24 used are high intensity neon lamps, such as thatsold under the designation C2A which give long life and highreliability. They require a high resistance in series with them, and ithas been found satisfactory to use resistances having a value of 33Kohms.

The circuit provides full voltage across the gaps 48 of the laminatepattern, which helps to ensure that the gaps will be bridged and thecircuits closed by pencil lead markings 19 on the answer sheet 18 whenthe same are pressed against the sensing panel board 22 by the pressurepad 88. I find this more reliable than to use a circuit which reducesthe voltage to say 20 volts and uses low voltage lamps, because at suchlow voltage the pencil markings do not reliably close the circuitsacross the gaps 48. The isolation transformer isolates the operatingcircuits from line potential and contributes to safety.

As previously indicated, the lamps 24 are desirably arranged in the sameangular spacing and the same order as the electrical gaps 48 to whichthey are connected. This correlates the lamps with the rows of answerspaces on the answer sheet being graded, and hence with the questionswhich have been answered. In order to show such correlation, a testquestion label disk 161 (FIG. 1) is desirably provided for each test,and this is placed within the ring of lamps 24 on the sensing panel in apredetermined orientation correlated with the orientation of the answersheet being graded. To secure the desired orientation of the label disk161, it is provided with a non-symmetrical pair of holes which fit overlocating posts 163. The label disk 161 may carry a series of numbers toindicate the test questions, but I have found it desirable to divide thedisk into subject categories correlated with the questions, so that thenumber of lamps which are lighted opposite each category indicates tothe student his level of performance in that category.

Operation of the test grading machine described above is as follows: Thestudent records his name, the test identification number and other datain the blank spaces at the center of an answer sheet 18, shown in FIG.2. The test to be answered is assumed to be a numbered series ofmultiple-choice test questions, each having four lettered answersbetween which the student is to choose. The student indicates hisselected responses to the numbered questions of the test by blacking-inwith a soft pencil one of the lettered answer spaces of eachcorrespondingly numbered row of such spaces on the answer sheet 18.

The same answer sheet is also usable for true/false tests. In such use,the student blacks in the two answer spaces marked A and B to register a"true" answer and blacks in the other two answer spaces marked C and Dto register a "false" answer.

When the student has completed the test, he takes the answer sheet 18 tothe test supervisor who consults the test master code sheet 38illustrated in FIG. 3 to determine the locations of the code punchingswhich are to be made to control the orientation of that test answersheet in the grading machine. The supervisor then punches theappropriate pair of opposed apertures through the peripheral markings 34on the sheet according to the markings identified by the code sheet. Healso selects an answer label disk 16 corresponding to the test beinggraded.

Either the supervisor or the student then places the answer sheet withinthe slot 16 of the grading machine between the upper sensing panel 14and the lower housing 12, and places the label disk 16 on the locatingpins 163 within the circle of lamps 24. The sheet 18 is horizontallysupported on the pressure pad 88 and on the border surfaces provided bythe front lip 55 and the horizontal legs of the side rails 60. The sheetis angularly oriented and located within the slot by engaging its twopunched holes (at rows 1 and 13 in FIGS. 1 and 2) over the locating pins39 at the sides of the housing.

The answer sheet is pressed into contact with the copper laminate gappattern 40 on the underside of the circuit board 22 by slightlydepressing the control lever 20, then pulling the handle 113 of the rod110 to release the latch 105 holding the crank bar 94, and thus allowingthe control lever 20 to rise, which allows the springs 78 to carry theplatform 86 upward. Desirably, the upward rate of travel of the platformis controlled by manually restraining the upward movement of the controlarm 20. The pressure pad 88 then presses the answer sheet firmly againstthe laminate pattern 40 on the circuit board so that blacked-in answerspaces 30 corresponding to correct responses are firmly pressed intobridging contact with the gaps 48 in that pattern. Such bridgingcontacts by correctly located responses marked on the sheet closecircuits to the corresponding lamps 24, to light such lamps. In anyanswer row 32 where an incorrect answer (or no answer) is given, the gap48 engaged by the unmarked correct answer space will not be bridged, andthe lamp circuit containing that gap 48 will not be closed and the lampwill remain dark.

The student can then observe and count the lighted lamps to determinethe number of questions on the test which he has correctly answered.Moreover, the student can observe the positions of the lighted and darklamps in relation to the label disk 161 on the sensing panel todetermine how well he performed in particular subject categories of thetest. From such observation, the student can then determine whether heshould proceed to the next block of instruction or should go back andstudy material in which he has done poorly.

The answer sheet 18 is released from the machine by pushing the controlarm 20 downward until the latch 105 re-engages over the crank bar 94 toagain lock the platform 86 is lowered position. The sheet can then beremoved from the slot 16 by lifting it off the pins 39 and pulling itout of the slot.

A test and grading apparatus of this invention is particularly usefulfor students who are following individualized courses of study and areadministering "self-tests" at periodic intervals. With this test scoringsystem, the student can proceed at his own rate and take any particularexamination for a block of instruction whenever he feels he is ready.The student can then obtain a quick, easy, and individual read-out ofhis performance on the particular instruction block by having his answersheet graded in the grading machine. For this, it is only necessary topunch peripheral apertures in the answer sheet according to the testunit number, insert the answer sheet in the machine in the orientationdetermined by that punching, and release the control linkage to raisethe pressure pad.

The test and scoring apparatus of this invention is particularlyadvantageous in that the machine can be used to grade answer sheets forseveral different test units in immediate succession and withoutadjustment or changing of the built-in answer code determined by thecooper laminate gap pattern. The only change needed is provided by thedifferent orientation punchings on different answer sheets. That is, thegap pattern defines a fixed code or sequence of answers, but thespecific starting point within that sequence and thus the specificanswer code for a particular examination unit depends upon the angularorientation of its answer sheet within the machine and with respect tothe laminate pattern. In the machine shown, there are twenty-fiveorientations which an answer sheet can have relative to the laminatepattern of gaps 48. The students will not know which orientation will beused on a particular test and hence will not normally be able todetermine which spaces represent correct answers. Several examinationunits can be graded with the same circuit board gap pattern withoutdanger that students will decipher the answer codes for such units. Thispermits many different examinations to be graded without any adjustmentof the machine itself, and therefore greatly simplifies the gradingoperation, and adapts the machine for grading a random succession ofanswer sheets for different examination units.

I claim:
 1. Test and grading apparatus, comprising:an answer sheethaving answer indicia thereon defining a circular series ofangularly-spaced row of radially-spaced answer spaces representingdifferent answers to questions of a series corresponding to the seriesof rows, said sheet being adapted to have answers indicated thereon bymarkings or the like at said answer spaces, said sheet also havingorientation indicia thereon to define a plurality of orientations inwhich the sheet may be applied to sensing means for scoring correctanswer markings thereon, sensing means having a circular series ofsensing elements angularly spaced for alignment with said rows of answerspaces and radially spaced for alignment with selected ones of theanswer spaces of the rows, to sense correct answers in such spaces,orientation means for selectively orienting answer sheets with respectto the sensing means in accordance with designated orientation indiciaon the answer sheets, means for bringing such answer sheets into sensingrelation with the sensing means in the designated orientations forsensing correct answers thereon, and indicating means to indicate forobservation the results of such sensing.
 2. Test and grading apparatusas in claim 1 in which said indicating means comprises a circle of lampsrespectively connected to the series of sensing means and arranged inthe same circular order, andcircuit means responsive to the sensingmeans for lighting the respective lamps in response to sensing ofcorrect answers by the sensing means.
 3. Test and grading apparatus asin claim 2 in which said answer spaces are adapted to be marked withelectrically-conductive marking material, and said sensing elementscomprise electrically-conductive materials defining gaps adapted to bebridged by the conductive material in correct answer spaces, saidcircuit means comprising parallel circuits respectively connecting theseveral gaps when bridged to energize the lamps.
 4. Test and gradingapparatus as in claim 2 with the addition of a label card correspondingto a particular set of test questions which are answered on an answersheet, means to mount such card in a predetermined orientation relativeto said circular series of lamps when that sheet is being sensed, saidcard having indicia thereon to correlate the lamps with the questions.5. Test and grading apparatus as in claim 1 in which said answer spacesare adapted to be marked with electrically-conductive marking material,and said sensing elements comprise electrical-conductive materialdefining gaps adapted to be bridged by the conductive marking materialin correct answer spaces, and circuit means responsive to the bridgingof said gaps and operative to actuate said indicating means.
 6. Test andgrading apparatus as in claim 1 in which the answer spaces are adaptedto be marked with electrically-conductive marking material, and saidsensing means comprises a circuit board having a pattern of conductivelaminate material thereon against which the answer sheets are broughtinto surface contact for sensing, said pattern defining electrical gapsin positions to be bridged by conductive markings in correct answerspaces on the answer sheet.
 7. Test and grading apparatus as in claim 6in which said indicating means comprises a series ofelectrically-operable individual indicating elements corresponding tothe series of row of answer spaces, and electrical circuit meansconnecting said indicating elements respectively for operation inresponse to bridging of said laminate gaps.
 8. Test and gradingapparatus as in claim 6 which includes a pressure plate for pressinganswer sheets into surface contact with said circuit board, springs orthe like for applying resilient pressure thereto, and manuallycontrolled means for moving the pressure plate toward and away from thecircuit board.
 9. Test and grading apparatus as in claim 6 whichincludes a pressure plate for pressing answer sheets into contact withthe circuit board, springs or the like constantly urging said platetoward the board, and manually operated control means for retracting theplate from the board.
 10. Test and grading apparatus as in claim 9 withthe addition of latch means for latching the plate in retractedposition.
 11. Test and grading apparatus as in claim 1 in which saidorientation indicia comprises a circular series of markings definingselective punch locations at which the sheet is to be punched todetermine the orientation in which it will be sensed, and saidorientation means comprises one or more locating pins or the likepositioned in a fixed relation with said sensing means and forengagement in the punchings of answer sheets presented for sensing bysaid sensing means so as to orient the same for such sensing.
 12. Testgrading apparatus for grading the answer markings on an answer sheethaving a circular series of equi-angularly spaced rows ofradially-spaced answer spaces thereon, comprisinga sensing panel havinga circular series of sensing elements arranged in angularly-spacedpositions for registry with the angularly-spaced rows of answer spacesand in radially-spaced positions to sense correct answers in selectedones of the answer spaces of the rows, said sensing panel therebydefining a circular reference code of correct answer positions and beingadapted to sense the set of answers on an answer sheet in any of aplurality of orientations of the answer sheet with respect thereto,orientation means for selectively orienting a particular answer sheetand the sensing panel in a particular orientation with respect to eachother, and means for bringing the answer sheet into sensing relationwith the sensing panel in such orientation.
 13. Test grading apparatusas in claim 12 in which said sensing elements comprise pairs ofelectrical contact surfaces defining gaps adapted to be bridged byelectrically-conductive markings in the answer spaces on the answersheet,a series of individual, electrically operated indicatorscorresponding to the series of sensing elements, and electrical circuitmeans connecting each gap in circuit with a different one of saidindicators to energize the same when the gap is bridged by a marking onan answer sheet.
 14. Test grading apparatus as in claim 13 in which theindicators are lamps.
 15. Test grading apparatus as in claim 14 in whichthe lamps are arranged in a circular series in the same order as thesensing elements.
 16. Test grading apparatus as in claim 15 with theaddition of means to support a selected label card adjacent said lampsto correlate them with the questions answered on the answer sheet. 17.Test grading apparatus as in claim 12 in which the sensing panel is acircuit board having a pattern of conductive laminate thereon, saidsensing elements being electrical gaps formed in said laminate patternadapted to be bridged by conductive markings on the answer sheet, andsaid means for bringing the sheet into sensing relation comprises apressure pad mounted for movement toward the circuit board to press theanswer sheet thereagainst.
 18. Test grading apparatus as in claim 17wherein the answer sheet to be graded is provided with a pair ofnon-symmetrical spaced punchings in orientation locations selected tomatch the test being answered, and said orientation means comprises apair of locating pins or the like positioned in fixed relation to saidcircuit board and for engagement by said punchings.
 19. A test gradingmachine for grading answer sheets having a circular pattern of indiciathereon defining a circular series of equi-angularly spaced rows ofradially spaced answer spaces, comprisinga housing having a sensingpanel mounted thereon, said housing and panel defining a slottherebetween for receiving an answer sheet in any of a plurality ofangular orientations therein, a sensing board mounted in said panel andfacing said slot, said board having a circular pattern of sensingelements thereon corresponding to a pattern of correct answer markingson an answer sheet, said pattern of sensing elements being engageable byanswer sheet in any of a plurality of angular orientations so as toprovide different angular positions of the correct answer pattern ondifferently oriented answer sheets, a platform movably mounted in thehousing, facing said circuit board and on the opposite side of the slotfrom such board, positioning means for locating and orienting an answersheet in said slot in a selected one of a plurality of angularorientations with respect to the sensing board and platform, means formoving the platform toward the sensing board to carry an oriented answersheet into sensing contact with the sensing elements thereon, andindicating means responsive to said sensing elements for indicatingcorrect answers on an answer sheet.
 20. A test grading machine as inclaim 19 in which said positioning means comprises a pair of locatingpins mounted in positions for engagement in punched openings in ananswer sheet inserted in said slot, so as to hold such answer sheet in aparticular location and orientation therein with respect to the platformand sensing board.
 21. A test grading machine as in claim 19 in whichsaid sensing board comprises a pattern of electrically-conductivelaminate on said circuit board and said sensing elements are electricalgaps formed in said laminate pattern and adapted to be bridged byelectrical marking material in answer spaces on the answer sheet tocomplete electrical circuits thereacross.
 22. A test grading machine asin claim 21 wherein said indicating means comprises a series of lampsmounted on said sensing panel, corresponding in number to the number ofsensing gaps in said laminate pattern, and circuit means connecting eachof said lamps with one of said gaps and operative to light the lamp whenthe gap is bridged.
 23. A test grading machine as in claim 22 which saidseries of lamps are mounted in a circle on said sensing panel insubstantial registry with the pattern of gaps on the sensing board, thelamps being generally in the same order and position as the gaps.
 24. Atest grading machine as in claim 19 in which said panel comprises aguideway and the sensing board is removably mounted in said guideway forready replacement by another board having a different pattern of sensingmeans thereon.
 25. A test grading machine as in claim 19 in which saidplatform moving means comprises one or more springs or the like mountedbetween the platform and housing and constantly urging the platformtoward the sensing board, a manually-operable control arm interconnectedto said platform for retracting the platform from the sensing board anda latch to retain the platform in retracted position.
 26. A test gradingmachine for grading answer sheets having a circular pattern of indiciathereon defining a circular series of equi-angularly spaced rows ofradially-spaced answer spaces, and on which answers are to be indicatedby marking selected ones of the spaces with electrically-conductivematerial, comprisinga base housing and a sensing panel mounted as acantilever over the housing to define a horizontal slot for receiving ananswer sheet to be graded, a sensing board mounted in said panel andfacing the slot, said board having electrical contacts thereon defininga circular pattern of electrical gaps thereon corresponding to a patternof correct answer markings on an answer sheet, said gap pattern beingengageable by answer sheets in any of a plurality of angularorientations so as to provide different angular positions of the correctanswer pattern on the differently oriented sheets, a platform movablymounted in the housing below the slot and movable upward to carry ananswer sheet thereon into contact with the gap pattern on the sensingboard, locating pins mounted laterally beside the sensing panel andprojecting upward from the housing, in position for engagement inpunched openings or the like in an answer sheet so as to hold the samein a particular orientation relative to the sensing board, means forlifting the platform toward the sensing board and resiliently pressingan oriented answer sheet into sensing contact with the gap on the board,manually operable arm connected for controlling the position of theplatform, and a circle of lamps mounted on the sensing panel above thesensing board, and circuit means connecting said lamps in parallel withthe respective gaps on the sensing board and operative to light eachlamp when its connected gap is bridged by a correct answer marking on ananswer sheet.